Low Temperature Synthesis of Mesoporous SiC in Dual-Confined Spaces via Magnesiothermic Reduction

Silicon carbide (SiC), especially mesoporous SiC has been in immense vogue for more than a decade because of its intriguing properties and wide applications. However, it is still challenging to synthesize mesoporous SiC with good structural integrality, large specific surface area and desirable porosity at a low temperature. In this study, we reported a "dual-confined spaces"assisted synthesis of mesoporous SiC using well-assembled SiO2/carbon composite as precursor via a magnesiothermic reduction process. The well-crystallinity mesoporous SiC presented a mesopore structure with high specific surface area of 267.3 m(2)g(-1) and large mesopore size of ca. 10 nm can be directly fabricated at a temperature of at least 550 degrees C and the optimum synthesis temperature is 650 degrees C. During the synthesis, mesoporous carbon matrix and a pressure-tight stainless steel reactor were served as "dual-confined spaces" to avoid the aggregation of silica and the silicon residue left in the final SiC sample. Furthermore, the as-prepared mesoporous SiC showed prominent performance as catalyst support for the reduction of 4-nitrophenol to 4-aminophenol.